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Mutations in a Plasmodium de-ubiquitinase UBP1 have been linked to antimalarial drug resistance. However, the UBP1-mediated drug-resistant mechanism remains unknown. Through drug selection, genetic mapping, allelic exchange, and functional characterization, here we show that simultaneous mutations of two amino acids (I1560N and P2874T) in the Plasmodium yoelii UBP1 can mediate high-level resistance to mefloquine, lumefantrine, and piperaquine. Mechanistically, the double mutations are shown to impair UBP1 cytoplasmic aggregation and de-ubiquitinating activity, leading to increased ubiquitination levels and altered protein localization, from the parasite digestive vacuole to the plasma membrane, of the P. yoelii multidrug resistance transporter 1 (MDR1). The MDR1 on the plasma membrane enhances the efflux of substrates/drugs out of the parasite cytoplasm to confer multidrug resistance, which can be reversed by inhibition of MDR1 transport. This study reveals a previously unknown drug-resistant mechanism mediated by UBP1 through altered MDR1 localization and substrate transport direction in a mouse model, providing a new malaria treatment strategy. Here, the authors show that two mutations in the Plasmodium de-ubiquitinase UBP1 alter the ubiquitination level, membrane localization, and ligand transport direction of multidrug resistance transporter 1 (MDR1), leading to multiple drug resistances. [ABSTRACT FROM AUTHOR]

To realize high performance flexible transparent electronics with extreme environmental adaptivity, Ag nanowires (Ag NWs) electrodes should simultaneously meet the requirements of high-temperature tolerance, chemical and mechanical robustness. Herein, a scalable Ag NWs bundle micro-meshes embedded in polyimide (Ag BMs/ePI) conducting film via a facile spray coating and transfer method is reported. Due to the synergistic effect of bundle micromesh and embedded architecture, the Ag BMs/ePI electrode exhibits high thermal stability (370 °C and 400 °C under ambient and nitrogen atmosphere conditions, respectively), low sheet resistance variation (<4%), good corrosion and deformation resistance. As an electrical heater, the Ag BMs/ePI can achieve ~204 °C with the fast thermal response time of ~8 s at 8 V, and exhibits good heating stability under bent condition. This work offers a promising platform for the emerging flexible transparent electronics to adapt extreme environments, especially for those devices which require high-temperature processing. [ABSTRACT FROM AUTHOR]

Quantitative myocardial contrast echocardiography (MCE) has been proved to be valuable in detecting myocardial ischemia. During quantitative MCE analysis, myocardial segmentation is a critical step in determining accurate region of interests (ROIs). However, traditional myocardial segmentation mainly relies on manual tracing of myocardial contours, which is time-consuming and laborious. To solve this problem, we propose a fully automatic myocardial segmentation framework that can segment myocardial regions in MCE accurately without human intervention. A total of 100 patients' MCE sequences were divided into a training set and a test set according to a 7: 3 proportion for analysis. We proposed a bi-directional training schema, which incorporated temporal information of forward and backward direction among frames in MCE sequences to ensure temporal consistency by combining convolutional neural network with recurrent neural network. Experiment results demonstrated that compared with a traditional segmentation model (U-net) and the model considering only forward temporal information (U-net + forward), our framework achieved the highest segmentation precision in Dice coefficient (U-net vs U-net + forward vs our framework: 0.78 ± 0.07 vs 0.79 ± 0.07 vs 0.81 ± 0.07, p < 0.01), Intersection over Union (0.65 ± 0.09 vs 0.66 ± 0.09 vs 0.68 ± 0.09, p < 0.01), and lowest Hausdorff Distance (32.68 ± 14.6 vs 28.69 ± 13.18 vs 27.59 ± 12.82 pixel point, p < 0.01). In the visual grading study, the performance of our framework was the best among these three models (52.47 ± 4.29 vs 54.53 ± 5.10 vs 57.30 ± 4.73, p < 0.01). A case report on a randomly selected subject for perfusion analysis showed that the perfusion parameters generated by using myocardial segmentation of our proposed framework were similar to that of the expert annotation. The proposed framework could generate more precise myocardial segmentation when compared with traditional methods. The perfusion parameters generated by these myocardial segmentations have a good similarity to that of manual annotation, suggesting that it has the potential to be utilized in routine clinical practice. [ABSTRACT FROM AUTHOR]

Purpose: Recent studies have reported important roles of dopamine receptors in the early development and progression of glioblastoma (GBM). Here, we tested the antitumor activity of a Dopamine receptor D1 (DRD1) agonist, either alone or in combination with temozolomide (TMZ) on GBM cells. Methods: Immunofluorescence, immunohistochemistry and Western blotting were used to detect dopamine receptor expression in primary human GBM tissues. In addition, clinical data of GBM patients downloaded from The Cancer Genome Atlas (TCGA) were analyzed. Image-based tracking analysis of LC3 using a mCherry-eGFP-LC3 plasmid was utilized to monitor autophagic flux. Transmission electron microscopy (TEM) was used to visualize aggregation of autophagosomes/autolysosomes. Finally, DRD1 agonist (SKF83959)-induced inhibition of GBM growth was assessed in vitro and in vivo. Results: Positive DRD1 expression was observed in human GBM tissues and found to be related with a good clinical outcome. DRD1 activation specifically inhibited GBM cell growth and significantly disrupted autophagic flux, which led to tumor cell death. Moreover, we found that DRD1 agonist treatment inhibited auto-lysosomal degradation in GBM cells and that this process was calcium overload dependent and related to inhibition of mammalian target of rapamycin (mTOR). Finally, we found that DRD1 agonist and TMZ co-treatment yielded a synergistic therapeutic effect both in vivo and in vitro. Conclusions: From our data we conclude that DRD1 activation inhibits GBM cell growth and may serve as an alternative avenue for the design of future GBM therapies. [ABSTRACT FROM AUTHOR]

Ribosomal protein s15a (RPS15A), a highly conserved cytoplasmic protein, promotes mRNA/ribosome interaction in translation. Recent evidence showed that RPS15A is essential for tumor growth. RPS15A expression level was measured in glioblastoma tissue samples and normal brain (NB) tissue samples. RPS15A RNAi stable cell line U87 and U251 was generated by the pLVTHM-GFP lentiviral RNAi expression system. The knockdown efficiency was confirmed by quantitative real-time PCR and western blot. Molecular mechanisms and the effect of RPS15A on cell growth and migration were investigated by using western blot, MTT assay, wound healing assay, transwell migration assay, and tumorigenesis in nude mice. Here, we report that RPS15A is overexpressed in human glioblastoma tumor tissues. RPS15A knockdown inhibits proliferation and migration of glioblastoma cells in vitro. Knocking down RPS15A leads to the level of p-Akt decrease and cell cycle arrested in G0/G1 phase in U87 and U251 cells. Furthermore, the growth of glioblastoma cell-transplanted tumors in nude mice is inhibited by transduction with Lv-shRPS15A. Our findings indicate that RPS15A promotes cell proliferation and migration in glioblastoma for the first time. RPS15A might play a distinct role in glioblastoma and serve as a potential target for therapy. [ABSTRACT FROM AUTHOR]

Key message: A dominantly inherited major-effect QTL for powdery mildew resistance in cucumber was fine mapped. Two tandemly arrayed cysteine-rich receptor-like protein kinase genes were identified as the most possible candidates. Abstract: Powdery mildew (PM) is one of the most severe fungal diseases of cucumber ( Cucumis sativus L.) and other cucurbit crops, but the molecular genetic mechanisms of powdery mildew resistance in cucurbits are still poorly understood. In this study, through marker-assisted backcrossing with an elite cucumber inbred line, D8 (PM susceptible), we developed a single-segment substitution line, SSSL0.7, carrying 95 kb fragment from PM resistance donor, Jin5-508, that was defined by two microsatellite markers, SSR16472 and SSR16881. A segregating population with 3600 F plants was developed from the SSSL0.7 × D8 mating; segregation analysis confirmed a dominantly inherited major-effect QTL, Pm1.1 in cucumber chromosome 1 underlying PM resistance in SSSL0.7. New molecular markers were developed through exploring the next generation resequenced genomes of Jin5-508 and D8. Linkage analysis and QTL mapping in a subset of the F plants delimited the Pm1.1 locus into a 41.1 kb region, in which eight genes were predicted. Comparative gene expression analysis revealed that two concatenated genes, Csa1M064780 and Csa1M064790 encoding the same function of a cysteine-rich receptor-like protein kinase, were the most likely candidate genes. GFP fusion protein-aided subcellular localization indicated that both candidate genes were located in the plasma membrane, but Csa1M064780 was also found in the nucleus. This is the first report of dominantly inherited PM resistance in cucumber. Results of this study will provide new insights into understanding the phenotypic and genetic mechanisms of PM resistance in cucumber. This work should also facilitate marker-assisted selection in cucumber breeding for PM resistance. [ABSTRACT FROM AUTHOR]